How to capture the text wthin the brackets: (), using regex maybe?

Question

any way would be fine. Perl, python, ruby...

Answer 1

You can match this regex

\(.*?\)

Edit:

The above regex will also include the brackets as a part of matched string. To avoid getting the brackets as a part of match (i.e. only match string inside the starting and ending bracket, excluding brackets) you may use below regex.

(?<=\().*?(?=\))

Answer 2

In perl, you can use this one,

Have a look

my $test = "Hello (Stack Overflow)";
   $test =~ /\(([^)]+)\)/;
my $matched_string = $1; 
print "$matched_string\n";  

OUTPUT:

Stack Overflow

Answer 3

Do you only want to match outer braces?

For example:

In Python:

s = "(here is some text for you (and me))"

import re
print ''.join(re.split(r"^\(|\)$", s))
# Returns "here is some text for you (and me)"

Otherwise:

s = "(here is some text for you (and me))"

import re
print [text for text in re.split(r"[()]", s) if text]
# Returns "['here is some text for you ', 'and me']"

Answer 4

On capturing groups

A capturing group, usually denoted with surrounding round brackets, can capture what a pattern matches. These matches can then be queried after a successful match of the overall pattern.

Here's a simple pattern that contains 2 capturing groups:

(\d+) (cats|dogs)
\___/ \_________/
  1        2

Given i have 16 cats, 20 dogs, and 13 turtles, there are 2 matches (as seen on rubular.com):

• 16 cats is a match: group 1 captures 16, group 2 captures cats
• 20 dogs is a match: group 1 captures 20, group 2 captures dogs

You can nest capturing groups, and there are rules specifying how they're numbered. Some flavors also allow you to explicitly name them.

References

• regular-expressions.info/Use Round Brackets for Capturing

---

On repeated captures

Now consider this slight modification on the pattern:

(\d)+ (cats|dogs)
\__/  \_________/
 1         2

Now group 1 matches \d, i.e. a single digit. In most flavor, a group that matches repeatedly (thanks to the + in this case) only gets to keep the last match. Thus, in most flavors, only the last digit that was matched is captured by group 1 (as seen on rubular.com):

• 16 cats is a match: group 1 captures 6, group 2 captures cats
• 20 dogs is a match: group 1 captures 0, group 2 captures dogs

References

• regular-expressions.info/Repeating a Capturing Group vs Capturing a Repeated Group

Related questions specific to .NET

• Is there a regex flavor that allows me to count the number of repetitions matched by * and +?
• What’s the difference between “groups” and “captures” in .NET regular expressions?
• Differences among .NET Capture, Group, Match